AQE 2021 Emissions Conference


The two-day Emissions Monitoring conference will focus on the latest issues relating to industrial emissions to air. The first AQE (Air Quality & Emissions) show took place in 2013, to build upon the previous ‘MCERTS’ events that began in 2002. The 2021 conference will focus on the measurement of low concentration emissions, biogenic carbon measurement, and mercury monitoring.

Day 1: Low emissions… a positive problem

As emissions reduction techniques become more effective and more widely adopted, and emissions regulations become tighter, the challenge for the emissions monitoring community is to be able to monitor pollutants at ever lower concentrations, accurately and reliably, in order to demonstrate compliance.

In common with previous events, the opening presentation will set the scene by describing the current international regulatory framework; summarising the current emissions reduction challenges and outlining the latest regulatory changes that have been implemented to meet these challenges.

The UK’s National Physical Laboratory (NPL) will then deliver a presentation on measurement uncertainty - a key issue for regulators, process operators and test laboratories. In particular, the presentation will address the performance of current reference methods at low emission concentrations since these reference methods are used to calibrate AMS. This is becoming a growing issue as regulations demand ever tighter emissions control, while abatement methods become more efficient, and monitoring technologies and methods become more sensitive.

David Graham, a technical consultant with Uniper, will then address the general EN 14181 quality assurance issues associated with the continuous emissions monitoring of gaseous and particulate pollutants at low concentration levels. The speaker will describe how these issues relate to the three Quality Assurance Levels: QAL1 (Certification); QAL2 (Calibration) and QAL3 (Control), as well as the Annual Surveillance Test (AST).

With a focus on particulate monitoring, the next presentation will discuss the monitoring of low particulate levels and the influences that particulate matter characteristics can have on automated measuring system (AMS) responses. The speaker will also address the potential technical issues arising when applying the Standard Reference Methods EN 13284-1 and EN 13284-2.

During QAL2 and AST testing for HCl monitoring, it is often difficult to obtain good agreement between test laboratory results and an installed AMS.  Andy Tiffen from Socotec will therefore discuss the known issues surrounding both SRM (Standard Reference Method) testing including best practice for test laboratories performing HCl testing, and the potential pitfalls for CEM systems (AMS). Suggestions will be provided for ways in which the results of EN 14181 calibrations can be improved.  This talk will also highlight additional areas of concern that require further research.

New continuous monitoring technologies, with superior sensitivity, better discrimination between gaseous components, and improved accuracy at low concentration levels, are able to rise to the challenge of measuring very low concentration levels, when suitably certified.

The application of OFCEAS (Optical Feedback Cavity Enhanced Absorption Spectroscopy) with Low Pressure sampling will be described. This technique is able to achieve very low levels of detection, with measurement ranges from parts per billion to percentage levels for standard gas species such as NOx, SO2, CO, CO2, H2O as well as gases of growing interest such as HCHO, H2S, HCl, CH4 and NH3.

Concluding the first day, Yves Tondeur (as a member of the US Source Evaluation Society) will provide a laboratory analytical perspective on the TEQ (Toxic Equivalent) representation of low concentration measurements of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, also referred to as dioxins) to ambient air. The speaker will describe the application of this work to the measurement of emissions from waste incineration, and explain why this is becoming an important issue in relation to the Maximum Achievable Control Technology (MACT) Standards.

Day 2 morning: Biogenic carbon measurement

The fight against climate change hinges greatly on a reduction in the use of fossil fuels, so recent years have seen the increasing use of fuels of biogenic origin as replacements for fossil fuels. However, the combustion of fuels with mixed and variable fossil and biogenic components presents a monitoring challenge because the biogenic CO2 within the flue gas needs to be discriminated from the fossil CO2.  This challenge will be addressed by several speakers in a session that will be chaired by Stewart Davies from Viridor.

Biogenic carbon emissions are those arising from what is often referred to as the natural carbon cycle, as well as those resulting from the combustion, decomposition and processing of biologically-derived carbon-containing materials. Examples of biogenic carbon emissions include those from: the combustion of biogas collected from the biological decomposition of waste in landfills, wastewater treatment, or manure management processes; the combustion of the biological fraction of municipal solid waste or biosolids; and emissions derived from the combustion of biological material, including forest-derived and agriculture-derived feedstocks.

In order to promote biogenic-based electricity generation, it is necessary to be able to reliably quantify the bio-based CO2 fraction in the flue gas of a mixed-fuel power plant.  With COP-26 taking place in Glasgow a few weeks after AQE 2021, and with many countries targeting Net-Zero, this session will address the urgent requirement to be able to reliably monitor this important and growing source of carbon emissions supporting more accurate, reliable and robust assessments of fossil and biogenic emissions in the flue gases of combustion plant and carbon capture systems.  Speakers will address the policy framework for the capture and storage carbon emissions; a process operator’s intended journey to achieving net-zero; and presenters who will describe the methods available for the measurement and quantification of biogenic and fossil CO2 in stack emissions from mixed-fuel combustion processes.

Day 2 afternoon: Global Mercury monitoring

The final session will focus on mercury monitoring and will be chaired by Dr Lesley Sloss. Lesley leads the United Nations Environment Programme Coal Partnership, providing expert advice to the negotiations on the Minamata Convention on Mercury.

Mercury was designated a chemical of global concern by the United Nations Environment Programme (UNEP) in 2006. This was because of its long-range transport capability in the atmosphere, its persistence in the environment, its toxicity, its ability to bio-accumulate in ecosystems and its harmful effects on human health.

As international regulations drive down the maximum allowable emission levels; methods, standards and technologies need to follow suit. But this can be challenging, given the technical limitations of some methods. Speakers, including Ben Freeman from the Environment Agency, will therefore provide a summary of the mercury monitoring requirements, challenges and solutions.

Mercury CEMs provide continuous data which creates a better picture of emissions and helps to highlight the causes of emission spikes. For this reason, continuous monitoring is becoming an increasing regulatory requirement for both Large Combustion Plant and Energy from Waste plant. However, CEMs represent a significant capital investment, particularly in comparison with the semi-continuous sorbent trap method, for example, so speakers will compare the relative merits of different approaches.